Dust collector

ABSTRACT

A dust collector includes an enclosure and a tube sheet separating filter and clean air compartments. The tube sheet forms a filter opening and a filter is located within the filter compartment and includes a filter flange having an air outlet aligned with said filter opening. The flange includes first and second alignment structures located on a first lateral side of the flange. A clamping assembly includes first and second filter clamps that are movable between a sealing position for sealing the filter flange against the tube sheet, and a release position. The first filter clamp engages the first alignment structure when in the sealing position. The second filter clamp engages the second alignment structure when in the sealing position. The dust collector includes means for moving the filter clamps between the sealing position and the release position.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 16/775,647 filed on Jan. 29, 2020, which is a division of U.S.patent application Ser. No. 15/902,006 filed Feb. 22, 2018 (now U.S.Pat. No. 10,821,391), the disclosures of which are incorporated hereinby reference.

BACKGROUND OF THE INVENTION Field of the Invention

Embodiments of the present invention relate to dust collectors and airfilters for use in dust collectors.

Description of Related Art

Dust collectors can be installed in fume extraction systems. Certainindustrial processes, such as welding, hardfacing, or plasma cutting cangenerate fumes and dust. Fume extraction systems can remove the fumesand dust from a space (e.g., a work area). Prior to discharging theremoved air to another space or outdoors, the air can be passed througha dust collector. The dust collector is an enclosure containing airfilters for cleaning the air of certain solid contaminants entrained inthe air. A tube sheet within the dust collector partitions the enclosureinto a clean air compartment and a filter compartment containingcontaminated air. The filters are sealed against the tube sheet.Contaminated air enters the filter compartment, passes through thefilters, then through an opening in the tube sheet and into the cleanair compartment. The cleaned air can be ducted to an appropriatedischarge location.

After a period of use, the filters are replaced. Misaligning a filterwithin the dust collector can negatively impact the performance of thedust collector, and could result in an improper seal of the filteragainst the tube sheet. Moreover, changing filters can betime-consuming. It would be desirable to provide a dust collector withan air filter clamping system that accurately positions the filters withrespect to the tube sheet and promotes quick replacement of the filters.

BRIEF SUMMARY OF THE INVENTION

The following summary presents a simplified summary in order to providea basic understanding of some aspects of the devices, systems and/ormethods discussed herein. This summary is not an extensive overview ofthe devices, systems and/or methods discussed herein. It is not intendedto identify critical elements or to delineate the scope of such devices,systems and/or methods. Its sole purpose is to present some concepts ina simplified form as a prelude to the more detailed description that ispresented later.

In accordance with one aspect of the present invention, provided is adust collector including an enclosure and a tube sheet separating afilter compartment from a clean air compartment within the enclosure.The tube sheet forms a filter opening through the tube sheet. A filteris located within the filter compartment and includes a filter flangehaving a filtered air outlet aligned with said filter opening. Thefilter flange includes a first alignment structure located on a firstlateral side of the filter flange, and a second alignment structurelocated on the first lateral side of the filter flange. The firstalignment structure is offset from the second alignment structure alongthe first lateral side of the filter flange. A clamping assemblycomprises a first filter clamp that is movable between a sealingposition for sealing the filter flange against the tube sheet, and arelease position. The first filter clamp engages the first alignmentstructure when in the sealing position. The clamping assembly comprisesa second filter clamp that is offset from the first filter clamp and ismovable between the sealing position for sealing the filter flangeagainst the tube sheet, and the release position. The second filterclamp engages the second alignment structure when in the sealingposition. The dust collector includes means for moving both of the firstfilter clamp and the second filter clamp together between the sealingposition and the release position.

In accordance with another aspect of the present invention, provided isa dust collector including an enclosure and a tube sheet separating afilter compartment from a clean air compartment within the enclosure.The tube sheet forms a filter opening through the tube sheet. A filteris located within the filter compartment and includes a filter flangehaving a filtered air outlet aligned with said filter opening. Thefilter flange includes a first alignment depression located on a firstlateral side of the filter flange, and a second alignment depressionlocated on the first lateral side of the filter flange. The firstalignment depression is offset from the second alignment depressionalong the first lateral side of the filter flange. A clamping assemblycomprises a first filter clamp that is movable between a sealingposition for sealing the filter flange against the tube sheet, and arelease position. A clamping surface of the first filter clamp islocated within the first alignment depression when the first filterclamp is in the sealing position. The clamping assembly comprises asecond filter clamp that is movable between the sealing position forsealing the filter flange against the tube sheet, and the releaseposition. A clamping surface of the second filter clamp is locatedwithin the second alignment depression when the second filter clamp isin the sealing position. A rotatable rail is attached to both of thefirst filter clamp and the second filter clamp and is configured formoving the first filter clamp and the second filter clamp between thesealing position and the release position. A locking handle is attachedto the rotatable rail for manually rotating the rotatable rail andlocking the rotatable rail in the sealing position of the first filterclamp and the second filter clamp.

In accordance with another aspect of the present invention, provided isan air filter including a filter flange comprising an upper gasketedsealing surface and a lower clamping surface, an end cap, and a filterelement located between the lower clamping surface of the filter flangeand the end cap. A first lateral side of the lower clamping surface ofthe filter flange includes a first clamping depression and a secondclamping depression. The first clamping depression and the secondclamping depression are linearly aligned along the first lateral side ofthe lower clamping surface, and the first clamping depression is offsetfrom the second clamping depression along the first lateral side of thelower clamping surface. A second lateral side of the lower clampingsurface of the filter flange includes a third clamping depression and afourth clamping depression, wherein the third clamping depression andthe fourth clamping depression are linearly aligned along the secondlateral side of the lower clamping surface, and the third clampingdepression is offset from the fourth clamping depression along thesecond lateral side of the lower clamping surface.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a dust collector;

FIG. 2 is a perspective view of the dust collector;

FIG. 3 is a perspective view of a portion of the dust collector;

FIG. 4 is a perspective view of a portion of the dust collector;

FIG. 5 is a perspective view of a filter;

FIG. 6 is a perspective view of the filter;

FIG. 7 shows a filter flange;

FIG. 8 shows the filter flange;

FIG. 9 is an elevation view of a portion of the dust collector;

FIG. 10 is an elevation view of a portion of the dust collector;

FIG. 11 is a perspective view of a portion of the dust collector;

FIG. 12 is a perspective view of a portion of the dust collector;

FIG. 13 is a perspective view of a filter clamping system; and

FIG. 14 is a perspective view of the filter clamping system.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention relate to dust collectors and airfilters for use in dust collectors. The present invention will now bedescribed with reference to the drawings, wherein like referencenumerals are used to refer to like elements throughout. It is to beappreciated that the various drawings are not necessarily drawn to scalefrom one figure to another nor inside a given figure, and in particularthat the size of the components are arbitrarily drawn for facilitatingthe understanding of the drawings. In the following description, forpurposes of explanation, numerous specific details are set forth inorder to provide a thorough understanding of the present invention. Itmay be evident, however, that the present invention can be practicedwithout these specific details. Additionally, other embodiments of theinvention are possible and the invention is capable of being practicedand carried out in ways other than as described. The terminology andphraseology used in describing the invention is employed for the purposeof promoting an understanding of the invention and should not be takenas limiting.

FIGS. 1 and 2 provide perspective views of an example dust collector 10having replaceable air filters. The dust collector 10 includes anenclosure 12 that forms a lower hopper 14, a central filter compartment16, and an upper clean air compartment 18. The filter compartment 16 isin fluid communication with the clean air compartment 18 through one ormore filters. In the embodiments discussed herein and shown in thefigures, the filter compartment 16 contains four filters. However, thefilter compartment 16 could contain more or fewer than four filters asdesired.

Contaminated air, generated at a workstation such as a welding or plasmacutting station, is drawn or pushed into the filter compartment 16 by ablower or fan 20. An air intake 22 is shown in FIG. 2. The air intake 22can be connected to ductwork (not shown) for conveying contaminated airto the dust collector 10. The fan 20 can provide an air outlet that maybe attached to additional clean air ductwork (not shown) for ventilationto a desired location. The fan 20 can be attached directly to the dustcollector 10 as shown, or the fan can be located remote from the dustcollector (in which case the clean air compartment 18 would include theair outlet).

Dust and other contaminants are removed from the contaminated air by thefilters within the filter compartment 16. The dust can fall into thehopper 14 and be discharged to a receptacle 24. The dust collector 10can include legs 26 to raise the enclosure 12 above the ground, so thatthe receptacle 24 can be placed beneath the hopper 14.

The dust collector 10 can include a control panel 28 having a userinterface for controlling the operation of the fan 20. The control panel28 can include indicators to inform a user that a filter requirescleaning or replacement (e.g., based on an increased pressure dropacross a filter). The control panel 28 can also include controls foractivating a filter cleaning system. The dust collector 10 can utilizeblasts of compressed air to “backwash” the filters and dislodge dustfrom the filter media. The dust collector 10 can include a compressedair tank 30 for storing compressed air provided by an air compressorthat is a part of the dust collector or located remote from the dustcollector. Valves, such as solenoid valves for example, control thedischarge of compressed air from the air tank 30 to the filters in aseries of pulses during a cleaning cycle. The clear air compartment 18can include respective air nozzles aligned with the filters to directthe air pulses in a reverse direction through the filters.

The dust collector 10 includes a door 32 on a front side of the dustcollector. The door 32 provides access to the filter compartment 16 toallow the filters to be replaced. The door 32 or enclosure 12 caninclude a gasket to seal the door against the enclosure when closed.

The interior of the filter compartment 16 and clean air compartment 18can be seen in FIG. 3. A tube sheet 34 separates the filter compartment16 from the clean air compartment 18. The tube sheet 34 has a series offilter openings 36 through the tube sheet. The clean air compartment 18is in fluid communication with the filter compartment 16 through thefilter openings 36, and filtered air enters the clean air compartment 16through the filter openings 36. The filters 38 are generallycylindrical, and air is drawn through the filter walls into the centerportion of the filter and upward to the clean air compartment throughthe filter openings 36 in the tube sheet 34.

FIG. 4 is an upward perspective view of the filter compartment 16. Eachfilter 38 has a filter flange 40 located at the top of the filter forsealing the filter against the lower surface of the tube sheet 34 andaround the filter openings in the tube sheet. As will be discussed indetail below, the filter compartment 16 includes a clamping system forclamping the filters against the tube sheet 34 and releasing the filtersso that they can be replaced. The clamping system can be manuallyoperable via interlockable clamp handles 42. In FIG. 4, the clamphandles 42 are shown in the sealing position, with the filter flanges 40sealed against the tube sheet 34. The clamp handles 42 can be lockedtogether at their distal ends to hold the filters 38 in the sealingposition. The clamp handles 42 can be moved to a release position sothat the filters can be removed. To do this, the distal ends of theclamp handles 42 are unlocked or detached from each other and rotateddownward through an acute angle (e.g., approximately 45°). To seal thefilters 34 against the tube sheet 34, the clamp handles 42 are rotatedupward through the acute angle, clockwise or counterclockwise, and thenlocked together.

The clamping system is configured to seal multiple filters 38 againstthe tube sheet 34 simultaneously. In FIG. 4, it can be seen that theleft and right portions of the clamping system each clamp two filterflanges 40 against the tube sheet 34. The clamping of two filter flanges40 can also be seen in FIGS. 11 and 12. The left and right portions ofthe clamping system are operable to simultaneously clamp an inner filterlocated adjacent a rear wall of the filter compartment 16, and an outerfilter located adjacent the clamp handles 42 and the access openingclosed by the door. If desired, clamping system can be configured toclamp fewer or more than four filters simultaneously.

The clamping system can be attached directly to the tube sheet 34, suchas via fasteners, welding, etc., or attached to other structures withinthe filter compartment 16.

The filter 38 is shown in detail in FIGS. 5-8. Extending downward fromthe filter flange 40 is a filter element 44. The filter element 44 caninclude a tube of filter media, such as a pleated cellulose media orother known filter materials. The lower end of the filter element 44 iscapped by an end cap 46. The filter flange 40 has a lower clampingsurface 48 and an upper gasketed sealing surface 50 that seals againstthe tube sheet. The filter element 44 of the air filter is locatedbetween the lower clamping surface 48 of the filter flange 40 and theend cap 46. The filter element 44 can be adhered to the filter flange 40and end cap 46, for example glued to the lower clamping surface 48 andend cap 46, to form air tight connections. The filter element 44 caninclude a series of bands 52 (e.g., polyester bands or other suitablematerial) to help maintain the cylindrical shape of the filter element,and the filter element can include a cylindrical inner structural cage(not shown) if desired.

The filter flange 40 can be substantially rectangular in shape, althoughother shapes are possible, such as square or octagonal for example. Thefilter flange 40 can have rounded or filleted corners and can take theform of a tray having upturned edges to strengthen the filter flange.The upper gasketed sealing surface 50 of the filter flange 40 is shownin FIG. 7, and the lower clamping surface 48 is shown in FIG. 8. It canbe seen that the filter flange 40 includes stamped or embossed portionsthat form depressions in the lower clamping surface 48 and raisedsurface features in the upper gasketed sealing surface 50.

The filter flange forms a central aperture 54 that is aligned with afilter opening in the tube sheet to allow filtered air to enter theclean air compartment. The central aperture 54 serves as a filtered airoutlet for the filter 38. The upper gasketed sealing surface 50 of thefilter flange 40 can include one or more gaskets 56 surrounding thecentral aperture 54 to seal flange against the tube sheet.Alternatively, one or more gaskets can be provided on the tube sheetitself. The gasket can be formed from an elastomeric material, such asEDPM rubber (ethylene propylene diene monomer rubber) for example. Inthe shown embodiment, the gaskets 56 are concentrically arranged withthe central aperture 54 and filter element 44 and are located on acircular raised surface feature 58 on the upper gasketed sealing surface50.

Forward 60 and rear 62 ends of the filter flange 40 extend betweenlateral (left and right) sides 64, 66 of the filter flange 40. In FIG.7, it can be seen that the filter flange 40 includes generally C-shapedraised surface features 68, 70 adjacent the forward 60 and rear 62 endsof the filter flange and continuing along the lateral sides 64, 66 for ashort distance past the corners of the flange. As will be explainedbelow, the C-shaped raised surface features 68, 70 can be utilized fromthe lower clamping surface 48 as handle depressions, and also asalignment structures (e.g., alignment or clamping depressions) thatinteract with the clamping system to properly position the filter 38within the dust collector.

The alignment or clamping depressions 72 in the lower clamping surface48 can be best seen in FIG. 8. The clamping depressions 72 are locatedalong the lateral sides 64, 66 of the filter flange 40, but could belocated at other locations on the filter flange if desired. Along eitherlateral side 64, 66, the clamping depressions 72 are linearly alignedwith and offset from each other to receive respective clamps in theclamping system. The filter element and gaskets are located between thecentral aperture 54 and the clamping depressions 72, and the clampingdepressions can be arranged symmetrically around the central aperture.

The handle depressions 74 extend between respective pairs of clampingdepressions 72 adjacent the forward and rear ends 60, 62 of the filterflange 40. The handle depressions 72 need not extend all the way fromone clamping depression 72 to another; however doing so allows a handledepression 74 and two clamping depressions 72 to be stamped into thefilter flange together by a common die. The handle depressions 74provide a handgrip to aid in inserting and removing the filters 38 fromthe dust collector, and also help to strengthen the filter flange. Inthe example embodiment shown, the filter flange 40 has two handledepressions 74, one at either end 60, 62. Thus, either end 60, 62 of thefilter flange 40 can be inserted into the filter compartment first whilestill providing a handgrip. However, if desired a single handledepression, or no handle depression, can be provided on the filterflange 40.

FIGS. 4 and 9-14 show details of the filter clamping system in the dustcollector 10. The clamping system is shown in the release position inFIGS. 10, 12 and 14, and in the sealing position in FIGS. 4, 9, 11 and13. The clamping system includes rotatable rails 76 that are eachattached to a respective clamp handle 42 at a proximal end of the clamphandle. The filters 38 are inserted onto the rotatable rails 76 with therails and handles 42 in the release position. The rotatable rails 76 canhave a generally L-shape as shown in the figures, or another suitableshape (e.g., C-shaped) that is capable of supporting the filter flanges40. Each rotatable rail 76 is sufficiently long to support multiple(e.g., two) filter flanges 40 simultaneously. When the clamp handles 42are rotated upward from a vertical orientation in the release positionthrough the acute angle to the sealing position, the filters 38 arelifted upward by rotation of the rails 76 and an upward rotation offilter clamps 78 attached to the rotatable rails 76. The filter clamps78 seat within corresponding clamping depressions 72 in the filterflange to seal the filter flange 40 against the tube sheet 34. If thefilters 38 are incorrectly installed in the dust collector 10, anoperator will become aware of the incorrect installation because thefilter gaskets 56 will be compressed against the tube sheet 34 beforethe clamp handles 42 are completely rotated through the acute angle tothe sealing position, since the filter clamps 78 will not be located inthe clamping depressions 72. The operator will be unable to properlyinterlock the clamp handles 42 because the distal ends of the clamphandles will be separated. Thus, the clamping depressions 72 serve asalignment structures for the filters 38.

The filter clamps 78 are configured as curved tabs that project outwardand downward from the rotatable rails 76 when the rails are in therelease position. The curved surfaces of the filter clamps 78 areclamping surfaces that engage the clamping depressions 72 in the filterflanges 40 when the rails 76 are in the sealing position. The curvedclamping surfaces act as cams that lift the filters 38 vertically as therotatable rails 76 are rotated through the acute angle to the sealingposition. When in the release position, the clamping surfaces of thefilter clamps 78 are located outside of the clamping depressions 72 inthe filter flanges 40 (e.g., located just beneath the clampingdepressions), and the filter flanges rest on the rails 76.

In the example dust collector 10 shown in the drawings, each filter 38is clamped in the sealing position by four filter clamps 78, two on theleft lateral side of the filter and two on the right lateral side of thefilter, and each rotatable rail 76 has eight attached filter clamps toseal and release two filters simultaneously. Additional clamps 78 couldbe utilized for each filter 38, such as three or four per lateral sidefor example.

The clamp handles 42 can be interlocked to maintain the filters 38raised in the sealing position. Interlocking the clamp handles 42 can bedone in various ways, such as by using a locking or fastening device(e.g., bolt, lock, shackle, etc.), or via interlocking componentslocated at the distal ends of the clamp handles. In the exampleembodiment shown in the figures, the distal ends of the clamp handles 42have a J-shape for capturing a cooperating clamp handle in ahandshake-like arrangement. The shapes of each handle 42 can beidentical, so that the handle can be installed on either a right lateralside or left lateral side rotatable rail.

The clamping system of the dust collector 10 includes clampingassemblies extending along the lateral sides of the filters. Theclamping assemblies include the clamp handles 42, rotatable rails 76,filter clamps 78, brackets for supporting the clamping system within thefilter compartment, and hinges for the rotatable rails.

The clamping assemblies can be configured to support a single rotatablerail 76 or multiple rotatable rails. The clamping assemblies on the farleft and right sides of the filter compartment include a singlerotatable rail 76. However, the clamping assembly in the center of thefilter compartment is located between all four filters 38 and includestwo rotatable rails 76 (one rail for clamping the two filters on theleft side of the filter compartment, and one rail for clamping the twofilters on the right side of the filter compartment).

Brackets 80, 82, 84, 86 having hinge pins 88 support the rotatable rails76 in the filter compartment 16. Pivot plates 90 are attached to therotatable rails 76 and the pivot plates rotate on the hinge pins 88. Thebrackets 80, 82, 84, 86 can include stop surfaces that limit theclockwise and counterclockwise rotation of the rails 76 within thebracket. For example, the brackets 80, 82, 84, 86 can include a ledge 92that limits the downward rotation of the rails 76 to the releaseposition, and an angled edge that limits the upward rotation of therails to the sealing position. Other types of stops could be provided onthe brackets 80, 82, 84, 86 to limit the rotation of the rails (e.g.,stops built into the hinge mechanism).

In the example embodiment shown in the drawings, each rail 76 issupported by four brackets. However, the rails 76 could be supported byfewer or more than four brackets. The forward-most brackets 80, 82 havefasteners for attaching the brackets to the tube sheet 34 or otherstructure in the filter compartment 16. The rear brackets 86, 88 lackfasteners and could be attached to the tube sheet or other structure bya welded connection for example.

It should be evident that this disclosure is by way of example and thatvarious changes may be made by adding, modifying or eliminating detailswithout departing from the fair scope of the teaching contained in thisdisclosure. The invention is therefore not limited to particular detailsof this disclosure except to the extent that the following claims arenecessarily so limited.

What is claimed is:
 1. An air filter, comprising: a filter flangecomprising a tray having a lower clamping surface, a second surfaceopposite the lower clamping surface, and an upwardly-projecting edgesurrounding the second surface of the tray, wherein the filter flangeforms a central aperture; an end cap; a filter element located betweenthe lower clamping surface of the filter flange and the end cap; and agasket concentric with the central aperture and located inward of theupwardly-projecting edge of the tray; wherein a first lateral side ofthe lower clamping surface of the filter flange includes a firstclamping depression and a second clamping depression, wherein the firstclamping depression and the second clamping depression are linearlyaligned along the first lateral side of the lower clamping surface, andthe first clamping depression is offset from the second clampingdepression along the first lateral side of the lower clamping surface,wherein a second lateral side of the lower clamping surface of thefilter flange includes a third clamping depression and a fourth clampingdepression, wherein the third clamping depression and the fourthclamping depression are linearly aligned along the second lateral sideof the lower clamping surface, and the third clamping depression isoffset from the fourth clamping depression along the second lateral sideof the lower clamping surface, and wherein the first clampingdepression, the second clamping depression, the third clampingdepression, and the fourth clamping depression form respective raisedsurface features on the second surface of the tray.
 2. The air filter ofclaim 1, wherein the filter flange includes a first end extendingbetween the first lateral side and the second lateral side, and a secondend extending between the first lateral side and the second lateralside, and the filter flange includes a handle depression formed in thelower clamping surface and adjacent at least one of the first end andthe second end, wherein the handle depression forms a further raisedsurface feature on the second surface of the tray.
 3. The air filter ofclaim 2, wherein the wherein the handle depression extends from thefirst clamping depression to the third clamping depression.
 4. The airfilter of claim 3, further comprising another handle depression formedin the lower clamping surface and located between the second clampingdepression and the fourth clamping depression.
 5. The air filter ofclaim 1, wherein the filter element is glued to the lower clampingsurface of the filter flange.
 6. The air filter of claim 5, furthercomprising a plurality of bands surrounding the filter element.
 7. Anair filter, comprising: a filter flange comprising a tray having a lowerclamping surface, a second surface opposite the lower clamping surface,and an upwardly-projecting edge surrounding the second surface of thetray, wherein the filter flange forms a central aperture; an end cap; afilter element located between the lower clamping surface of the filterflange and the end cap; and a gasket concentric with the centralaperture and located inward of the upwardly-projecting edge of the tray;wherein: a first lateral side portion of the lower clamping surface ofthe filter flange includes a first clamping depression, a second lateralside portion of the lower clamping surface of the filter flange includesa second clamping depression, and the first clamping depression forms afirst raised surface feature on the second surface of the tray, and thesecond clamping depression forms a second raised surface feature on thesecond surface of the tray.
 8. The air filter of claim 7, wherein thefilter flange includes a first end extending between the first lateralside portion and the second lateral side portion, and a second endextending between the first lateral side portion and the second lateralside portion, and the filter flange includes a handle depression formedin the lower clamping surface and adjacent at least one of the first endand the second end, wherein the handle depression forms a further raisedsurface feature on the second surface of the tray.
 9. The air filter ofclaim 8, wherein the handle depression extends from the first clampingdepression to the second clamping depression.
 10. The air filter ofclaim 9, further comprising another handle depression formed in thelower clamping surface.
 11. The air filter of claim 7, wherein thefilter element is glued to the lower clamping surface of the filterflange.
 12. The air filter of claim 11, further comprising a pluralityof bands surrounding the filter element.
 13. An air filter, comprising:a filter flange comprising a tray having a lower clamping surface, asecond surface opposite the lower clamping surface, and anupwardly-projecting edge surrounding the second surface of the tray,wherein the filter flange forms a central aperture; an end cap; a filterelement located between the lower clamping surface of the filter flangeand the end cap; and a gasket concentric with the central aperture andlocated inward of the upwardly-projecting edge of the tray; wherein: afirst lateral side portion of the lower clamping surface of the filterflange includes a first clamping depression and a second clampingdepression, a second lateral side portion of the lower clamping surfaceof the filter flange includes a third clamping depression and a fourthclamping depression, and the first clamping depression forms a firstraised surface feature on the second surface of the tray, the secondclamping depression forms a second raised surface feature on the secondsurface of the tray, the third clamping depression forms a third raisedsurface feature on the second surface of the tray, and the fourthclamping depression forms a fourth raised surface feature on the secondsurface of the tray.
 14. The air filter of claim 13, wherein the filterflange includes a first end extending between the first lateral sideportion and the second lateral side portion, and a second end extendingbetween the first lateral side portion and the second lateral sideportion, and the filter flange includes a handle depression formed inthe lower clamping surface and adjacent at least one of the first endand the second end, wherein the handle depression forms a further raisedsurface feature on the second surface of the tray.
 15. The air filter ofclaim 14, wherein the handle depression extends from the first clampingdepression to the third clamping depression.
 16. The air filter of claim15, further comprising another handle depression formed in the lowerclamping surface and located between the second clamping depression andthe fourth clamping depression.
 17. The air filter of claim 13, whereinthe filter element is glued to the lower clamping surface of the filterflange.
 18. The air filter of claim 17, further comprising a pluralityof bands surrounding the filter element.